Glossary: d-NTSC & d-PAL

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Glossary: d-NTSC & d-PAL

Mark Filipak (ffmpeg)
Continuing with relatively non controversial entries:

d-NTSC [noun]: 1, The digital equivalent of NTSC distinguished by
   binary metadata:
   720 samples/row: 'horizontal_size_value' = 0010 1101 0000
                    'horizontal_size_extension' = 00
   480 rows: 'vertical_size_value' = 0001 1110 0000
             'vertical_size_extension' = 00
   4:3 DAR: 'aspect_ratio_information' = 0010
   30/1.001 FPS: 'frame_rate_code' = 0100
   'progressive_sequence' = 0 & 'progressive_frame' = 0

d-PAL [noun]: 1, The digital equivalent of PAL distinguished by binary
   metadata:
   720 samples/row: 'horizontal_size_value' = 0010 1101 0000
                    'horizontal_size_extension' = 00
   576 rows: 'vertical_size_value' = 0010 0100 0000
             'vertical_size_extension' = 00
   4:3 DAR: 'aspect_ratio_information' = 0010
   25 FPS: 'frame_rate_code' = 0011
   'progressive_sequence' = 0 & 'progressive_frame' = 0

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Re: Glossary: d-NTSC & d-PAL

Jim DeLaHunt-2
On 2020-09-30 20:36, Mark Filipak (ffmpeg) wrote:

> Continuing with relatively non controversial entries:
>
> d-NTSC [noun]: 1, The digital equivalent of NTSC distinguished by
>   binary metadata:
>   720 samples/row: 'horizontal_size_value' = 0010 1101 0000
>                    'horizontal_size_extension' = 00
>   480 rows: 'vertical_size_value' = 0001 1110 0000
>             'vertical_size_extension' = 00
>   4:3 DAR: 'aspect_ratio_information' = 0010
>   30/1.001 FPS: 'frame_rate_code' = 0100
>   'progressive_sequence' = 0 & 'progressive_frame' = 0
>
> d-PAL [noun]: 1, The digital equivalent of PAL distinguished by binary
>   metadata:
>   720 samples/row: 'horizontal_size_value' = 0010 1101 0000
>                    'horizontal_size_extension' = 00
>   576 rows: 'vertical_size_value' = 0010 0100 0000
>             'vertical_size_extension' = 00
>   4:3 DAR: 'aspect_ratio_information' = 0010
>   25 FPS: 'frame_rate_code' = 0011
>   'progressive_sequence' = 0 & 'progressive_frame' = 0


It seems to me that these are no longer glossary entries — or, only the
first line of each is a glossary entry. The rest seems to be a
description of a data structure or representation. The entry doesn't say
to what format or specification the representation applies. To an MPEG-2
video? To a the ISO file corresponding to a DVD?

       —Jim DeLaHunt


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Re: Glossary: d-NTSC & d-PAL

Mark Filipak (ffmpeg)
On 09/30/2020 11:56 PM, Jim DeLaHunt wrote:

> On 2020-09-30 20:36, Mark Filipak (ffmpeg) wrote:
>
>> Continuing with relatively non controversial entries:
>>
>> d-NTSC [noun]: 1, The digital equivalent of NTSC distinguished by
>>   binary metadata:
>>   720 samples/row: 'horizontal_size_value' = 0010 1101 0000
>>                    'horizontal_size_extension' = 00
>>   480 rows: 'vertical_size_value' = 0001 1110 0000
>>             'vertical_size_extension' = 00
>>   4:3 DAR: 'aspect_ratio_information' = 0010
>>   30/1.001 FPS: 'frame_rate_code' = 0100
>>   'progressive_sequence' = 0 & 'progressive_frame' = 0
>>
>> d-PAL [noun]: 1, The digital equivalent of PAL distinguished by binary
>>   metadata:
>>   720 samples/row: 'horizontal_size_value' = 0010 1101 0000
>>                    'horizontal_size_extension' = 00
>>   576 rows: 'vertical_size_value' = 0010 0100 0000
>>             'vertical_size_extension' = 00
>>   4:3 DAR: 'aspect_ratio_information' = 0010
>>   25 FPS: 'frame_rate_code' = 0011
>>   'progressive_sequence' = 0 & 'progressive_frame' = 0
>
>
> It seems to me that these are no longer glossary entries — or, only the first line of each is a
> glossary entry. ...

Each entry is just one sentence, so I guess you don't like the sentence spanning multiple lines (?)

The sentence is a statement followed by a list of metadata that distinguishes the subject... so that
people can determine whether a particular video is a d-NTSC video or not a d-NTSC video for example.
The main distinguishing feature is 'progressive_sequence' = 0 & 'progressive_frame' = 0 of course.
The others narrow the scope to just a single species of video.

If a glossary entry requires explanation, then it's a fail. What fails? I guess I didn't anticipate
such a total-failure mode.

Do you have any suggestions? Should I just forget this glossary idea?

>... The rest seems to be a description of a data structure or representation. The entry
> doesn't say to what format or specification the representation applies. To an MPEG-2 video? To a the
> ISO file corresponding to a DVD?


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Re: Glossary: d-NTSC & d-PAL

Jim DeLaHunt-2
On 2020-10-01 06:27, Mark Filipak (ffmpeg) wrote:

> On 09/30/2020 11:56 PM, Jim DeLaHunt wrote:
>> On 2020-09-30 20:36, Mark Filipak (ffmpeg) wrote:
>>
>>> Continuing with relatively non controversial entries:
>>>
>>> d-NTSC [noun]: 1, The digital equivalent of NTSC distinguished by
>>>   binary metadata:
>>>   720 samples/row: 'horizontal_size_value' = 0010 1101 0000
>>>                    'horizontal_size_extension' = 00
>>>   480 rows: 'vertical_size_value' = 0001 1110 0000
>>>             'vertical_size_extension' = 00
>>>   4:3 DAR: 'aspect_ratio_information' = 0010
>>>   30/1.001 FPS: 'frame_rate_code' = 0100
>>>   'progressive_sequence' = 0 & 'progressive_frame' = 0
>>>
>>> d-PAL [noun]: 1, The digital equivalent of PAL distinguished by binary
>>>   metadata:
>>>   720 samples/row: 'horizontal_size_value' = 0010 1101 0000
>>>                    'horizontal_size_extension' = 00
>>>   576 rows: 'vertical_size_value' = 0010 0100 0000
>>>             'vertical_size_extension' = 00
>>>   4:3 DAR: 'aspect_ratio_information' = 0010
>>>   25 FPS: 'frame_rate_code' = 0011
>>>   'progressive_sequence' = 0 & 'progressive_frame' = 0
>>
>>
>> It seems to me that these are no longer glossary entries — or, only
>> the first line of each is a glossary entry. ...
>
> …The sentence is a statement followed by a list of metadata that
> distinguishes the subject...
> Do you have any suggestions? Should I just forget this glossary idea?


What makes sense to me is a glossary which includes the entries:

d-NTSC [noun]: 1, The digital equivalent of NTSC

d-PAL [noun]: 1, The digital equivalent of PAL

Then a table of XYZ metadata entries which have been found in the wild:

[Display the following table with fixed-width font]

Kind of data   |                          Metadata field entries
                |  Metadata key               | Metadata value | Meaning
---------------+-----------------------------+----------------+----------------
d-NTSC         | 'horizontal_size_value' | 0010 1101 0000 | 720 samples/row
                | 'horizontal_size_extension' | 00       |
                | 'vertical_size_value' | 0001 1110 0000 | 480 rows
                | 'vertical_size_extension'   | 00             |
                | 'aspect_ratio_information'  | 0010           | 4:3 DAR
                | 'frame_rate_code' | 0100           | 30/1.001 FPS
                | 'progressive_sequence' | 0              |
                | 'progressive_frame' | 0             |
---------------+-----------------------------+----------------+----------------
d-PAL          | 'horizontal_size_value' | 0010 1101 0000 | 720 samples/row
                | 'horizontal_size_extension' | 00             |
                | 'vertical_size_value' | 0010 0100 0000 | 576rows
[… etc …]

And, you need to fill in "XYZ", which stands for the context: metadata
of which format or specification?  Of an MPEG-2 video? Of the ISO file
corresponding to a DVD? Of something else?

       —Jim DeLaHunt


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Re: Glossary: d-NTSC & d-PAL

Mark Filipak (ffmpeg)
On 10/01/2020 01:03 PM, Jim DeLaHunt wrote:

> On 2020-10-01 06:27, Mark Filipak (ffmpeg) wrote:
>
>> On 09/30/2020 11:56 PM, Jim DeLaHunt wrote:
>>> On 2020-09-30 20:36, Mark Filipak (ffmpeg) wrote:
>>>
>>>> Continuing with relatively non controversial entries:
>>>>
>>>> d-NTSC [noun]: 1, The digital equivalent of NTSC distinguished by
>>>>   binary metadata:
>>>>   720 samples/row: 'horizontal_size_value' = 0010 1101 0000
>>>>                    'horizontal_size_extension' = 00
>>>>   480 rows: 'vertical_size_value' = 0001 1110 0000
>>>>             'vertical_size_extension' = 00
>>>>   4:3 DAR: 'aspect_ratio_information' = 0010
>>>>   30/1.001 FPS: 'frame_rate_code' = 0100
>>>>   'progressive_sequence' = 0 & 'progressive_frame' = 0
>>>>
>>>> d-PAL [noun]: 1, The digital equivalent of PAL distinguished by binary
>>>>   metadata:
>>>>   720 samples/row: 'horizontal_size_value' = 0010 1101 0000
>>>>                    'horizontal_size_extension' = 00
>>>>   576 rows: 'vertical_size_value' = 0010 0100 0000
>>>>             'vertical_size_extension' = 00
>>>>   4:3 DAR: 'aspect_ratio_information' = 0010
>>>>   25 FPS: 'frame_rate_code' = 0011
>>>>   'progressive_sequence' = 0 & 'progressive_frame' = 0
>>>
>>>
>>> It seems to me that these are no longer glossary entries — or, only the first line of each is a
>>> glossary entry. ...
>>
>> …The sentence is a statement followed by a list of metadata that distinguishes the subject...
>> Do you have any suggestions? Should I just forget this glossary idea?
>
>
> What makes sense to me is a glossary which includes the entries:
>
> d-NTSC [noun]: 1, The digital equivalent of NTSC
>
> d-PAL [noun]: 1, The digital equivalent of PAL
>
> Then a table of XYZ metadata entries which have been found in the wild:
Actually, not in the wild. They are from H.262.

> [Display the following table with fixed-width font]

Actually, Jim, what you sent is not in fixed-width font. :-)
So, you favor a formal table? I don't, but I guess that could go without saying, eh?
I format in plain text at 148 columns. I've found 70 columns to be too restricting and promotes
crypticism (...is there such a word?). Personally, I don't think formal tables are needed, but if
you do, then I'll make a formal table. But first, take a look at the current version, attached.

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d-NTSC & d-PAL .txt (1K) Download Attachment
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Re: Glossary: d-NTSC & d-PAL

FFmpeg-users mailing list
 I don't know who's in charge of this glossary project, but can I please propose something on the difference between colourspace, subsampling and luminance encoding. And all the other things people constantly confuse.
P  
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Re: Glossary: d-NTSC & d-PAL

Mark Filipak (ffmpeg)
On 10/01/2020 02:01 PM, Phil Rhodes via ffmpeg-user wrote:
>   I don't know who's in charge of this glossary project, but can I please propose something on the difference between colourspace, subsampling and luminance encoding. And all the other things people constantly confuse.

No one's in charge. I've taken the initiative to begin (and conduct and finish and whatever it
takes) the effort [1]. Based on the evidence, I'm not alone, but no one's in charge.

Regarding your concerns, Phil, I believe I have a lock on subsampling & luminance encoding (or, at
least, the structures, but not the processes) and I would post glossary entries if I could, but
they're very large and have large texie pix diagrams and are formatted to 148 columns of text and
therefore don't fit into email format, and I would probably incur the ire of the list maintainers if
I were to attach such large files. Sorry,

Regarding colorspace, such documentation exists, at least in name -- literally, names only to the
best of my knowledge -- but the details of the data structures are, at best: buried in code
algorithms without explicit structural documentation, or, at worst: completely lacking and subject
to trial-and-error hacking, even by the developers.

[1] There are 3 ways to take leadership: #1, be appointed by some authority, or #2, be elected by
some constituency, or #3, start leading. I have tried #1 and #2 and have not been successful due to
wrangling, so I am pursuing route #3. If that rankles some folks, the fault is entirely mine.

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Re: Glossary: d-NTSC & d-PAL

Jim DeLaHunt-2
In reply to this post by Mark Filipak (ffmpeg)
On 2020-10-01 10:50, Mark Filipak (ffmpeg) wrote:

> On 10/01/2020 01:03 PM, Jim DeLaHunt wrote:
>> On 2020-10-01 06:27, Mark Filipak (ffmpeg) wrote:
>>
>>> On 09/30/2020 11:56 PM, Jim DeLaHunt wrote:
>>>> On 2020-09-30 20:36, Mark Filipak (ffmpeg) wrote:
>>>>
>>>>> Continuing with relatively non controversial entries:
>>>>>
>>>>> d-NTSC [noun]: 1, The digital equivalent of NTSC distinguished by
>>>>>   binary metadata:
>>>>>   720 samples/row: 'horizontal_size_value' = 0010 1101 0000
>>>>>                    'horizontal_size_extension' = 00
>>>>>   480 rows: 'vertical_size_value' = 0001 1110 0000
>>>>>             'vertical_size_extension' = 00
>>>>>   4:3 DAR: 'aspect_ratio_information' = 0010
>>>>>   30/1.001 FPS: 'frame_rate_code' = 0100
>>>>>   'progressive_sequence' = 0 & 'progressive_frame' = 0
>>>>>
>>>>> d-PAL [noun]: 1, The digital equivalent of PAL distinguished by
>>>>> binary
>>>>>   metadata:
>>>>>   720 samples/row: 'horizontal_size_value' = 0010 1101 0000
>>>>>                    'horizontal_size_extension' = 00
>>>>>   576 rows: 'vertical_size_value' = 0010 0100 0000
>>>>>             'vertical_size_extension' = 00
>>>>>   4:3 DAR: 'aspect_ratio_information' = 0010
>>>>>   25 FPS: 'frame_rate_code' = 0011
>>>>>   'progressive_sequence' = 0 & 'progressive_frame' = 0
>>>>
>>>>
>>>> It seems to me that these are no longer glossary entries — or, only
>>>> the first line of each is a glossary entry. ...
>>>
>>> …The sentence is a statement followed by a list of metadata that
>>> distinguishes the subject...
>>> Do you have any suggestions? Should I just forget this glossary idea?
>>
>>
>> What makes sense to me is a glossary which includes the entries:
>>
>> d-NTSC [noun]: 1, The digital equivalent of NTSC
>>
>> d-PAL [noun]: 1, The digital equivalent of PAL
>>
>> Then a table of XYZ metadata entries which have been found in the wild:
>
> Actually, not in the wild. They are from H.262.


OK, then I think what you have — what you put in your text attachment
"d-NTSC & d-PAL .txt" in your previous message — is two single-line
glossary entries, conjoined with entries from a table mapping H.262
Metadata Values to video types d-NTSC and d-PAL.

I think it is clearer to have the mapping from H.262 Metadata Values in
a separate structure from the glossary. You seem to want to combine
them. I disagree with this editorial choice, but you hold the pen and I
don't care to pick it up.

>> [Display the following table with fixed-width font]
>
> Actually, Jim, what you sent is not in fixed-width font. :-)


I won't try to explain the vagaries of how my client formats messages,
how the list reformats them, and how your client displays them. I think
it's more accurate to say that what I sent was plain text, which looks
better displayed in a fixed-width font, but maybe your client chose to
display it using a variable-width font.

Plain-text emails are only good for certain kinds of content. They can
represent some table layouts, but not others. This thread appears to be
taking tables beyond what plain-text emails can handle.

        —Jim DeLaHunt



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Re: Glossary: d-NTSC & d-PAL

Mark Filipak (ffmpeg)
On 10/01/2020 03:21 PM, Jim DeLaHunt wrote:
-snip-
> OK, then I think what you have — what you put in your text attachment "d-NTSC & d-PAL .txt" in your
> previous message — is two single-line glossary entries, conjoined with entries from a table mapping
> H.262 Metadata Values to video types d-NTSC and d-PAL.

Well, that deserves an answer. There are two parts to each glossary entry: 1, A simple statement of
what a thing is, and 2, a "distinguished by" identification so that readers can identify the thing.
The table is the "distinguished by" part. I formatted it as a table to make it easy, or at least so
I thought! :-)

For example, d-NTSC is distinguished via MPEG-PS binary metadata:
'progressive_sequence' == 0 & 'progressive_frame' == 0 & 'aspect_ratio_information' == 0010 &
'frame_rate_code' == 0100 & 'horizontal_size_value' == 0010 1101 0000 & 'horizontal_size_extension'
== 00 & 'vertical_size_value' == 0001 1110 0000 & 'vertical_size_extension' == 00.

That's the logic. Putting the table into a different glossary entry wouldn't work, but obviously,
the way I'm doing it now is a FAIL.

I'll try again.

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Re: Glossary: d-NTSC & d-PAL

Mark Filipak (ffmpeg)
On 10/01/2020 05:13 PM, Mark Filipak (ffmpeg) wrote:
> On 10/01/2020 03:21 PM, Jim DeLaHunt wrote >> OK, then I think what you have — what you put in your text attachment "d-NTSC & d-PAL .txt" in
>> your previous message — is two single-line glossary entries, conjoined with entries from a table
>> mapping H.262 Metadata Values to video types d-NTSC and d-PAL.
-snip-
> I'll try again.

How's this look, Jim? Clear? Or muddled?

d-NTSC [noun]: The digital equivalent of NTSC. d-NTSC is distinguished
   by a frame having all 8, MPEG-PS binary metadata values below.
    'aspect_ratio_information' = 0010              [1]
             'frame_rate_code' = 0100              [1]
       'horizontal_size_value' = 0010 1101 0000    [1]
         'vertical_size_value' = 0001 1110 0000    [1]
   'horizontal_size_extension' = 00                [2]
     'vertical_size_extension' = 00                [2]
        'progressive_sequence' = 0                 [2]
           'progressive_frame' = 0                 [3]
   [1] From sequence_header
   [2] From sequence_extension
   [3] From picture_coding_extension

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Re: Glossary: d-NTSC & d-PAL

Jim DeLaHunt-2
In reply to this post by Mark Filipak (ffmpeg)
On 2020-10-01 14:13, Mark Filipak (ffmpeg) wrote:

> On 10/01/2020 03:21 PM, Jim DeLaHunt wrote:
> -snip-
>> OK, then I think what you have — what you put in your text attachment
>> "d-NTSC & d-PAL .txt" in your previous message — is two single-line
>> glossary entries, conjoined with entries from a table mapping H.262
>> Metadata Values to video types d-NTSC and d-PAL.
>
> Well, that deserves an answer. There are two parts to each glossary
> entry: 1, A simple statement of what a thing is, and 2, a
> "distinguished by" identification so that readers can identify the thing.

You are making an author's choice to put #2 in the glossary. I maintain
that #2 is something different, and does not belong in a glossary. In my
opinion only #1 belongs in the glossary.  #2 belongs in, for example, a
description of the structures found in MPEG-PS streams according to
H.262 (or something like that).

You seem to want to combine them. I disagree with this editorial choice,
but you hold the pen and I don't care to pick it up.


On 2020-10-01 14:49, Mark Filipak (ffmpeg) wrote:

> On 10/01/2020 05:13 PM, Mark Filipak (ffmpeg) wrote:
>> On 10/01/2020 03:21 PM, Jim DeLaHunt wrote >> OK, then I think what
>> you have — what you put in your text attachment "d-NTSC & d-PAL .txt" in
>>> your previous message — is two single-line glossary entries,
>>> conjoined with entries from a table mapping H.262 Metadata Values to
>>> video types d-NTSC and d-PAL.
> -snip-
>> I'll try again.
>
> How's this look, Jim? Clear? Or muddled?
>
> d-NTSC [noun]: The digital equivalent of NTSC. d-NTSC is distinguished
>   by a frame having all 8, MPEG-PS binary metadata values below.
>    'aspect_ratio_information' = 0010              [1]
>             'frame_rate_code' = 0100              [1]
> [… snip …]


It is an improvement that you are now stating the context, "MPEG-PS
binary metadata values". You omitted that context before. But you
continue to put #2 in the glossary entry, and I continue to be of the
opinion that the glossary is the wrong place for the content.   The
details of the table formatting of #2 is a side issue in this discussion.

       —Jim DeLaHunt


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Re: Glossary: d-NTSC & d-PAL

Mark Filipak (ffmpeg)
> On 2020-10-01 14:49, Mark Filipak (ffmpeg) wrote:
>> On 10/01/2020 05:13 PM, Mark Filipak (ffmpeg) wrote:
>>> On 10/01/2020 03:21 PM, Jim DeLaHunt wrote >> OK, then I think what you have — what you put in
>>> your text attachment "d-NTSC & d-PAL .txt" in
>>>> your previous message — is two single-line glossary entries, conjoined with entries from a table
>>>> mapping H.262 Metadata Values to video types d-NTSC and d-PAL.
>> -snip-
>>> I'll try again.
>>
>> How's this look, Jim? Clear? Or muddled?
>>
>> d-NTSC [noun]: The digital equivalent of NTSC. d-NTSC is distinguished
>>   by a frame having all 8, MPEG-PS binary metadata values below.
>>    'aspect_ratio_information' = 0010              [1]
>>             'frame_rate_code' = 0100              [1]
>> [… snip …]
>
>
> It is an improvement that you are now stating the context, "MPEG-PS binary metadata values". You
> omitted that context before. But you continue to put #2 in the glossary entry, and I continue to be
> of the opinion that the glossary is the wrong place for the content.   The details of the table
> formatting of #2 is a side issue in this discussion.

What is #2?


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Re: Glossary: d-NTSC & d-PAL

Jim DeLaHunt-2
On 2020-10-01 15:37, Mark Filipak (ffmpeg) wrote:

> On 2020-10-01 15:30, Jim DeLaHunt wrote:
>>
>> It is an improvement that you are now stating the context, "MPEG-PS
>> binary metadata values". You omitted that context before. But you
>> continue to put #2 in the glossary entry, and I continue to be of the
>> opinion that the glossary is the wrong place for the content.   The
>> details of the table formatting of #2 is a side issue in this
>> discussion.
>
> What is #2?


"#1" and "#2" is your notation, in a message I quoted in my reply. You
elided that quote in your reply. Here it is:

On 2020-10-01 14:13, Mark Filipak (ffmpeg) wrote:

> On 10/01/2020 03:21 PM, Jim DeLaHunt wrote:
> -snip-
>> OK, then I think what you have — what you put in your text attachment
>> "d-NTSC & d-PAL .txt" in your previous message — is two single-line
>> glossary entries, conjoined with entries from a table mapping H.262
>> Metadata Values to video types d-NTSC and d-PAL.
>
> Well, that deserves an answer. There are two parts to each glossary
> entry: 1, A simple statement of what a thing is, and 2, a
> "distinguished by" identification so that readers can identify the thing.

So:

"#1" is "A simple statement of what a thing is", and
"#2" is "a 'distinguished by' identification so that readers can
identify the thing".

       —Jim DeLaHunt

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Re: Glossary: d-NTSC & d-PAL

Mark Filipak (ffmpeg)
On 10/01/2020 10:42 PM, Jim DeLaHunt wrote:

> On 2020-10-01 15:37, Mark Filipak (ffmpeg) wrote:
>
>> On 2020-10-01 15:30, Jim DeLaHunt wrote:
>>>
>>> It is an improvement that you are now stating the context, "MPEG-PS binary metadata values". You
>>> omitted that context before. But you continue to put #2 in the glossary entry, and I continue to
>>> be of the opinion that the glossary is the wrong place for the content.   The details of the
>>> table formatting of #2 is a side issue in this discussion.
>>
>> What is #2?
>
>
> "#1" and "#2" is your notation, in a message I quoted in my reply. You elided that quote in your
> reply.

Ah! Thank you, Jim. ...senior moment :-)

I INTERRUPT THIS PROGRAM FOR AN IMPORTANT ANNOUNCEMENT.

The text two paragraphs below was my original response. I include it just for the sake of
completeness and for Jim's benefit, however, things have... progressed (in a way).

My goal (for a long time) is to differentiate hard telecine from pseudo NTSC (which I'm calling
d-NTSC). I thought I'd found the differentiation: The combined values of 'progressive_sequence' and
'progressive_frame' MPEG-PS metadata. I was wrong. The video that I thought was hard telecined was
actually soft telecined. When I realized my error, I revised my response:
"'progressive_sequence' = 0 & 'progressive_frame' = 1 means that the frame is soft telecined",
and only then realized that I'd screwed the pooch: that I still had no way to differentiate hard
telecine from d-NTSC. I'm withdrawing the d-NTSC & d-PAL entries and will rework them when I can, in
fact, differentiate d-NTSC & d-PAL from hard telecine. (sigh!)

WE NOW RESUME OUR REGULARLY SCHEDULED PROGRAM.

If I understand your point, it is that the definition is followed by a table (of sorts) that you
think is content and not a suitable part of the definition. Okay, let me try to explain and maybe
you can suggest a better way, eh?

The 'table' isn't really a table. It's the metadata values that are necessary for the d-NTSC frame
to be a d-NTSC frame. I provide it so that readers can verify that, "Yes, indeed, I'm looking at a
d-NTSC frame". The big clue is that 'progressive_sequence' (from the sequence_extension metadata
structure) and 'progressive_frame' (from the picture_coding_extension metadata structure) are both
zero. My friend, it took me months to figure that out because H.262 doesn't put things together.
Here's the straight dope:
'progressive_sequence' = 1 means the frame is a picture.
'progressive_sequence' = 0 & 'progressive_frame' = 0 means that the frame is d-NTSC or d-PAL.
'progressive_sequence' = 0 & 'progressive_frame' = 1 means that the frame is soft telecined.

Without that info, you can't tell d-NTSC from hard telecined unless you single step through the
video frames and know what to look for.

The other metadata in the 'table' is the rest of the stuff that distinguishes d-NTSC from d-PAL:
width, height, aspect ratio, etc.

So, you see, the metadata has to be part of the definition, or at least that's what I think.

Do you have a better idea?

--
What if you woke up and found yourself in a police state?
African-Americans wake up in a police state every day.

--
What if you woke up and found yourself in a police state?
African-Americans wake up in a police state every day.
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Re: Glossary: d-NTSC & d-PAL

Jim DeLaHunt-2
On 2020-10-03 08:44, Mark Filipak (ffmpeg) wrote:

> …I INTERRUPT THIS PROGRAM FOR AN IMPORTANT ANNOUNCEMENT.
>
> The text two paragraphs below was my original response. I include it
> just for the sake of completeness and for Jim's benefit, however,
> things have... progressed (in a way).
>
> My goal (for a long time) is to differentiate hard telecine from
> pseudo NTSC (which I'm calling d-NTSC). I thought I'd found the
> differentiation: The combined values of 'progressive_sequence' and
> 'progressive_frame' MPEG-PS metadata. I was wrong. The video that I
> thought was hard telecined was actually soft telecined. When I
> realized my error, I revised my response:
> "'progressive_sequence' = 0 & 'progressive_frame' = 1 means that the
> frame is soft telecined",
> and only then realized that I'd screwed the pooch: that I still had no
> way to differentiate hard telecine from d-NTSC. I'm withdrawing the
> d-NTSC & d-PAL entries and will rework them when I can, in fact,
> differentiate d-NTSC & d-PAL from hard telecine. (sigh!)
>
> WE NOW RESUME OUR REGULARLY SCHEDULED PROGRAM.
>
> If I understand your point, it is that the definition is followed by a
> table (of sorts) that you think is content and not a suitable part of
> the definition. Okay, let me try to explain and maybe you can suggest
> a better way, eh?
>
> The 'table' isn't really a table. It's the metadata values that are
> necessary for the d-NTSC frame to be a d-NTSC frame. I provide it so
> that readers can verify that, "Yes, indeed, I'm looking at a d-NTSC
> frame". The big clue is that 'progressive_sequence' (from the
> sequence_extension metadata structure) and 'progressive_frame' (from
> the picture_coding_extension metadata structure) are both zero. My
> friend, it took me months to figure that out because H.262 doesn't put
> things together. Here's the straight dope:
> 'progressive_sequence' = 1 means the frame is a picture.
> 'progressive_sequence' = 0 & 'progressive_frame' = 0 means that the
> frame is d-NTSC or d-PAL.
> 'progressive_sequence' = 0 & 'progressive_frame' = 1 means that the
> frame is soft telecined.
>
> Without that info, you can't tell d-NTSC from hard telecined unless
> you single step through the video frames and know what to look for.
>
> The other metadata in the 'table' is the rest of the stuff that
> distinguishes d-NTSC from d-PAL: width, height, aspect ratio, etc.
>
> So, you see, the metadata has to be part of the definition, or at
> least that's what I think.
>
> Do you have a better idea?


When you say, "My goal (for a long time) is to differentiate hard
telecine from pseudo NTSC (which I'm calling d-NTSC).… [using] MPEG-PS
metadata", it sounds to that your goal is to describe different content
structures in the context of an MPEG-PS stream. The right document for
doing this work is a guide to or explanation of MPEG-PS stream contents.
As part of describing a content structure, it is probably quite helpful
to list the metadata values which identify that structure. But this
document is not a glossary.

It also sounds to me like you are coining the term "d-NTSC" to name one
kind of content structure. It is perfectly in scope to define names in
such a guide or explanation.  But it sounds like you aren't claiming
that the term "d-NTSC" is [also] defined by some other document, such as
the H.262 specification. Fine.

In the glossary, I would expect to see a term, e.g. "d-NTSC", and then
one or more entries describing meanings of that term, each with an
explanation of the term and a cross-reference to where the term is
defined or used in an important way, e.g. to "Mark's Guide to MPEG-PS
Stream Content Structures", section X.Y, "pseudo-NTSC content".

Or simply put, what you are drafting in this thread is an entry in
Mark's Guide to MPEG-PS, not a glossary entry. In my humble opinion.

       —Jim DeLaHunt



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Re: Glossary: d-NTSC & d-PAL

Mark Filipak (ffmpeg)
On 10/03/2020 08:09 PM, Jim DeLaHunt wrote:
> On 2020-10-03 08:44, Mark Filipak (ffmpeg) wrote:
-snip-> When you say, "My goal (for a long time) is to differentiate hard telecine from pseudo NTSC
(which
> I'm calling d-NTSC).… [using] MPEG-PS metadata", it sounds to that your goal is to describe
> different content structures in the context of an MPEG-PS stream.

That is exactly what I'm doing. I've been (manually) parsing a lot of video sequences (meaning the
stream beginning with 'sequence_header_code': 0x00 00 01 B3, and ending with 'sequence_end_code':
(0x00 00 01 B7 -- I'm not interested in the transport packages, though I've parsed them, too)
looking for clues to formats. I spent over a month just figuring out macroblock structures.

> The right document for doing this
> work is a guide to or explanation of MPEG-PS stream contents. As part of describing a content
> structure, it is probably quite helpful to list the metadata values which identify that structure.
> But this document is not a glossary.

Why not? (That question is rhetorical ... I appreciate that you have a right to your own opinion.)

> It also sounds to me like you are coining the term "d-NTSC" to name one kind of content structure.
> It is perfectly in scope to define names in such a guide or explanation.  But it sounds like you
> aren't claiming that the term "d-NTSC" is [also] defined by some other document, such as the H.262
> specification. Fine.

H.262 (and presumably MPEG) don't name things. For example, H.262 refers to d-NTSC & d-PAL (i.e.
scan-frames) by citing metadata thusly: "If progressive_frame is set to 0 it indicates that the two
fields of the frame are interlaced fields in which an interval of time of the field period [1]
exists between (corresponding spatial samples) of the two fields." -- how cumbersome! I'm just
assigning names to the 30/1.001 Hz & 25 Hz versions.

> In the glossary, I would expect to see a term, e.g. "d-NTSC", and then one or more entries
> describing meanings of that term, each with an explanation of the term and a cross-reference to
> where the term is defined or used in an important way, e.g. to "Mark's Guide to MPEG-PS Stream
> Content Structures", section X.Y, "pseudo-NTSC content".
>
> Or simply put, what you are drafting in this thread is an entry in Mark's Guide to MPEG-PS, not a
> glossary entry. In my humble opinion.

So, I take it that, to you, a glossary is a snack whereas a meal must be some sort of treatise and
that you think a meal is required. I disagree, but maybe you're right.

Perhaps a presentation of my motives is in order? -- I DO have an axe to grind. :-)

Treatises drive me nuts. I better understand a complicated subject by hacking between and among
concise definitions. I rarely read treatises because they always seem to explain by citing use
cases. With each use case, the architecture comes into better focus, but it does take relearning
over and over and that takes so much time. I'm a computer system architect. Kindly just give me the
structure and the procedure and I'll put it together. I don't need use cases. (Code would probably
be sufficient, but I don't know 'C'.)

When presented with a treatise, what I do is scan it -- I never exhaustively read it -- and build a
glossary. Then, to really understand the topic, I scan the glossary, pulling threads together in my
mind until I've formed an architecture. Then I test the architecture against the treatise's use
cases. I don't think I'm alone in this. In the case of ffmpeg, everything seems to be use cases and
it drives me postal.

--
--
What if you woke up and found yourself in a police state?
African-Americans wake up in a police state every day.
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